Deploying Tactic costs Tactic Points; you are unable to deploy Tactic with insufficient Tactic Point.

Tactic Point can be recovered in following ways:

(1). Auto recover: it recovers 1 point every half an hour until it is full.

(2). Purchase: it costs 250 diamonds for 50 Tactic Points.

(3). Battlefield update: it recovers 60 Tactic Points in every update; can't obtain Tactic Points anymore when it is full.